Which statement best describes a typical high-voltage connection for a 9-lead motor?

Which statement best describes a typical high-voltage connection for a 9-lead motor?

• A. Pair leads 1&7 to L1, 2&8 to L2, 3&9 to L3; 4,5,6 tied; coils in series.
• B. Pair leads 1&7 to L1, 2&8 to L2, 3&9 to L3; 4,5,6 tied; coils in parallel.
• C. Connect all leads to a single phase.
• D. Connect 1-9 in a straight delta.

Answer: (A)

High-voltage operation with a 9-lead motor uses windings in series so each winding carries part of the total voltage, while the same current flows through all of them. In this arrangement three identical winding sections form the phase path. Feeding the lines through paired leads that are ends of each winding, and tying the remaining leads together to form the series chain, achieves this. Specifically, connecting 1 and 7 to L1, 2 and 8 to L2, and 3 and 9 to L3 supplies each phase, while tying 4, 5, and 6 together creates the junctions between windings. This puts the windings in series for high voltage and keeps the conductors’ voltages and currents balanced across the three phases. The other options would either place windings in parallel (low-voltage configuration), connect all windings to a single phase (violating three-phase operation), or describe a configuration that doesn’t realize the standard high-voltage series connection for a nine-lead motor.

High-voltage operation with a 9-lead motor uses windings in series so each winding carries part of the total voltage, while the same current flows through all of them. In this arrangement three identical winding sections form the phase path. Feeding the lines through paired leads that are ends of each winding, and tying the remaining leads together to form the series chain, achieves this. Specifically, connecting 1 and 7 to L1, 2 and 8 to L2, and 3 and 9 to L3 supplies each phase, while tying 4, 5, and 6 together creates the junctions between windings. This puts the windings in series for high voltage and keeps the conductors’ voltages and currents balanced across the three phases. The other options would either place windings in parallel (low-voltage configuration), connect all windings to a single phase (violating three-phase operation), or describe a configuration that doesn’t realize the standard high-voltage series connection for a nine-lead motor.